Conventionally, an electrical connection box has been known in which a circuit board such as a printed circuit board is contained in a case so as to enable a conductive member connected to the circuit board to be connected to an electrical component such as a fuse. In particular, in recent years, accompanying demand for better space efficiency and higher density in electrical connection boxes, an electrical connection box has been known which includes a lateral component connection portion having multiple electrical component mounting portions that open laterally on a side surface thereof. The technique disclosed in JP 2014-165960A (JP 2014-165960A) is an example thereof.
In order to provide this kind of lateral component connection portion on the circuit board, it is necessary to bend the end portions of the conductive members connected to the circuit board such as substrate terminals or busbars into L shapes to cause connection terminals provided on the end portions to protrude toward the side edge portion of the circuit board in a direction of being level with the circuit board, as shown in FIG. 3 of JP 2014-165960A. Then, a lateral component connection portion is formed by containing and disposing the multiple connection terminal portions from rearward in component mounting holes that are provided so as to penetrate in the horizontal direction through the lateral component connection portion, in a state in which the multiple connection terminal portions are disposed in alignment in the width direction and height direction of the lateral component connection portion. In short, with the electrical connection box disclosed in JP 2014-165960A, the rear portions of the component mounting holes of the lateral component connection portion are used as terminal holding portions, and the front portions of the component mounting holes are used as electrical component mounting portions. Accordingly, the connection terminals can be contained from behind the component mounting holes, the electrical components can be mounted from the front of the component mounting holes, and the terminal holding portions and the electrical component mounting portions are integrated, whereby a reduction of the number of components is achieved.
Incidentally, with respect to these electrical component mounting portions of the lateral component connection portion mounted on the circuit board, when an electrical component is attached to or removed from an electrical component mounting portion provided on the side of the electrical connection box, or in other words, on the front portion of a component mounting hole, and a tab terminal of the electrical component is attached to or removed from a connection terminal portion provided on a substrate terminal or a busbar arranged rearward of the component mounting hole, an insertion or removal force is applied to the connection terminal portion in the direction of being level with the circuit board. For this reason, as disclosed in JP 2014-165960A, the conventional lateral component connection portion is constituted by including an insulation plate including supporting pins that are placed on the circuit board and protrude perpendicularly to the circuit board, and a component holding case into which the support pins can be inserted, the component holding case being assembled on the insulation plate and including component holding holes that penetrate therethrough in the direction of being level with the circuit board. Also, a structure is employed in which multiple supporting pins that are provided so as to protrude on the insulation plate are engaged with recessed and protruding engagement portions that are provided on the connection terminal portions arranged inside of the component holding case, and the above-described insertion or removal force is supported by the support pins.
However, it is not easy to perform the task of engaging the supporting pins that protrude in the direction orthogonal to the circuit board with the engagement portions of the connection terminal portions that extend in the direction of being level with the circuit board, and depending on the dimensional intersection, inclination, and the like of the supporting pins, there is an inherent possibility that the engagement of the supporting pins with the engagement portions will be incomplete. Furthermore, due to the fact that a structure is used in which the component holding case of the lateral component connection portion is oriented so as to be open on the lateral surface of the electrical connection box and the terminal holding portions and the electrical component mounting portions are integrated, a structure is used in which the upper portion and lateral portion of the component holding case are covered by an upper wall and a lateral wall, as shown in FIG. 4 of JP 2014-165960A. For this reason, there is an inherent problem in that when assembling the component holding case from above on the insulation plate on which the supporting pins are provided, an assembly worker is blocked by the upper wall of the terminal holding case and has difficulty checking the state of engagement between the supporting pins and the engagement portions, and therefore cannot easily detect incomplete engagement between the supporting pins and the engagement portions.
The present invention has been made in light of circumstances such as those disclosed above, and the problem to be solved lies in providing an electrical connection box including a new structure, according to which it is possible to easily check the engagement between connection terminal portions and supporting pins in a lateral component connection portion, and to simultaneously achieve an improvement in the workability and the reliability of assembly and an improvement in work efficiency due to a reduction in the number of components, even in the case of using a component holding case in which the terminal holding portions and the electrical component mounting portions are integrated.